The U.S. Coast Guard needs a little extra muscle in Bar Harbor during the summer, so it has called in a big gun.

The Coast Guard has what it calls an extra “29-foot Response Boat-Small” patrolling during cruise ship season this summer, said Nicole Groll, a petty officer with the Coast Guard’s Boston office.

The boat is crewed by about a half-dozen guardsman who carry a lot of law enforcement equipment, including a machine gun at the bow. The M240B is a general-purpose weapon that fires about 950 7.62-mm rounds per minute, Groll said.

The boat is working routine, annual and supplemental security detail guarding cruise ships, their tenders and other traffic as it transits Frenchman Bay and the harbor.

Based in New York City, this particular Marine Safety and Security Team was brought in to escort cruise ship tenders on their rounds and to provide security for cruise ships during cruise ship season, Groll said.

“It’s a deterrent. Cruise ships are big and international, and they have a lot of people aboard,” Groll said Tuesday. “We do these patrols all the time, so for me, there is nothing uncommon about them.”

The boats guard against destruction, loss or injury from crime, or sabotage due to terrorist or criminal activity — or, as Groll puts it, “people being foolish.”

The Coast Guard station at Southwest Harbor also provides such security. It has its own 29-footer and is out there every day, but has many other missions besides guarding cruise ships, Groll said, so the Coast Guard rotates extra teams in during the summer.

Sometimes the extra boat comes from Cape Cod, but this year, New York got the call. The Coast Guard pays for the patrols out of its operational budget, she said.

Correction:The photo caption in an earlier version of this story gave the impression the boat pictured is the same one patrolling the waters near Bar Harbor this year, when it was a 25-foot boat from 2016.